The purpose of this study is to examine the safety and effectiveness (how well it works) of T-20 in the treatment of HIV infection. During this study, the subject will receive treatment with T-20 alone for ten days, and then receive T-20 along with nevirapine, nelfinavir, and saquinavir for approximately 24 weeks. Nevirapine, nelfinavir and saquinavir are approved medications that are currently available for the treatment of HIV infection by prescription from a doctor.